CHAPTER III
"TEMPEST" OF THE AERIAL POLICE

Colonel John Tempest, D.S.O., M.C., etc., late of the Royal Air Force, and now Chief Commissioner of the British Aerial Police, sat before a pile of papers in his office at Scotland Yard late one evening. He was anxious and worried, for something had gone seriously wrong with his plans.

It was his duty to investigate and track down all aerial criminals, whether brigands, smugglers or revolutionists of the Bolshevist type. For this purpose he had been appointed by the Government to the command of the British Aerial Police, whose functions included the patrolling of the routes of the great aerial liners throughout the British Isles, and the All-Red route to Egypt, India, and other British possessions, and the careful guarding and watching of the aerial gateways and ports.

Some of the best scout pilots of the war, including two famous secret service men, named Keane and Sharpe, were detailed to assist him in this important and ever-increasing task, for aerial crime of twenty different kinds was becoming more and more prevalent since the war.

So far his efforts had been conspicuously successful, and he had brought many of the offenders to justice, but at the present moment he had to confess himself baffled–utterly baffled by a series of unfortunate occurrences which it had been beyond his power to prevent.

"There is some master-mind behind all this," he exclaimed to himself, rising suddenly from his chair, and beginning to pace the room, much in the same way that he used to pace his squadron office, in the old days, when, as commander of a squadron of scouts during the Great War, he had attempted to outwit the daring of the German airmen.

"I wonder now–I wonder what happened to that missing German professor!" and Colonel Tempest suddenly halted, and placed his left hand to his forehead, as some powerful, new idea had arrested his mental faculties.

Then, walking across the room swiftly, he switched on a shaded light which illuminated a large map of Germany, showing the aerial routes, the lines of occupation by the Allies, etc.

"It is just possible," he murmured to himself, "that the two things are connected–the disappearance of this eminent scientist and the appearance of this extraordinary flying machine." Then he switched off the light, and returned to the sheaf of papers and documents on his desk. He sorted out one and placed it on top; it was a decoded message, received some days ago from one of his agents at Constantinople. It ran as follows:–

"Mysterious aeroplane, phantom-like in appearance, passed over here yesterday flying at terrific speed. All our signals disregarded. No navigation lights showing. Our fast scouts gave chase but left hopelessly behind. Came from direction of Adrianople, crossed the Bosphorus, and disappeared rapidly flying south-east. Time shortly after sunset.

AERIAL, CONSTANTINOPLE."

"That is three days ago," continued the Colonel, still thinking aloud, "and here are four similar messages from other sources showing quite plainly the route taken. Great Heavens! if I were not tied to my desk in this place, I would take the fastest scout in the country and chase this infernal night-wizard myself."

A soft tap at the door startled the Commissioner, for during the last three days he had become highly nervous; this affair was getting on his mind, but he recovered himself instantly and called out in a deep voice:–

"Come in!"

The door opened softly and his confidential secretary entered, and announced:–

"Two more cables and a wireless message, sir."

"Anything from Keane or Sharpe yet?" demanded the chief.

"Nothing, sir."

"Then what are these confounded things?"

"More about that aerial brigand, sir."

"Let me see them," and Jones handed the messages to his chief.

Consternation and alarm were both visible on the face of Tempest as he read the news.

"So the devil has already got to work, Jones," he remarked, quoting from the sheets, laconic phrases such as "Oil tanks at Port Said burning for three days. Crew of mysterious aeroplane suspected." (Delayed in transit.) "Wireless station at Karachi utterly destroyed, after brief visit by strange airmen." The third was a wireless message which proved most disconcerting of all to the Commissioner. It announced that a silent aeroplane, showing no distinctive marks whatever, passed over Delhi "this afternoon" at a speed estimated at not less than three hundred miles an hour.

The chief of the aerial police leaned back in his chair and groaned.

"Three hundred miles an hour!" he gasped; "but the silent aeroplane idea is a fallacy. It is impossible with any type of internal-combustion engine. It must either have been too high up for the good people of Delhi to hear it, or its engines must have been shut off, or well throttled down. Bah! I know too much about aeroplanes to swallow that." Then rounding upon Jones, who was standing by awaiting instructions, he said sharply:–

"Did that second message go out to Keane?"

"Yes, sir."

"And there's still no reply from him?"

"Nothing whatever, sir."

"H'm. I cannot understand it. Send it out again by wireless telephone; he may be on his way back by aeroplane now, and possibly within reach."

"Right, sir," and Jones disappeared to stab the ether waves again in search of Keane. At that moment the telephone bell on the Commissioner's desk rang. It was the Home Secretary asking for Colonel Tempest, for the same messages concerning the aerial brigand had reached him.

"Hello, Tempest; is that you?"

"Yes; who is that?"

"Lord Hamilton, speaking from the Home Office."

"Oh, yes, my lord."

"I say, Tempest, what is this news just to hand about aerial highwaymen romping half round the British empire, destroying wireless stations, and burning out the big oil tanks along the All-Red Route? I thought you had all these aerial criminals well in hand. There'll be a deuce of a row about all this when Parliament meets in two days' time."

"Well, er–we're doing our best to deal with it, sir, but it will take time to lay these fellows by the heel, I fear."

"Have you got the matter in hand?"

"Yes, sir."

"What have you done? I shall be bombarded with questions shortly; in fact, the Colonial Secretary's here now. He's complaining that the routes are not sufficiently well patrolled. What steps have you taken to deal with these marauders?"

"I've wirelessed to all the aerial stations, to get their fastest scouts out all along the line at once to look for these bandits, and I'm staying on here all night expecting news every moment."

"Very well. Keep me informed of everything that happens. It's becoming very serious. You have full powers to deal effectively with these criminals, and they may be shot down at sight if they don't respond to signals."

Then, as the angry minister rang off, another tap was heard at the door, and the imperturbable Jones entered once more, and announced:

"Message from Keane and Sharpe came in whilst you were speaking on the telephone, sir."

"Good!" ejaculated Tempest, as he wiped the perspiration from his brow, for he had expected something much worse from the Home Secretary. "What does the message say?"

"They received my last message, sir, and are on their way home by the fastest aeroplane. They are due at Hounslow aerodrome at midnight."

"Excellent! What time is it now, Jones?"

"It wants ten minutes to midnight, sir, and I have sent out the fastest car to meet them and bring them straight here. They should be here in half an hour, sir."

"Have you told them at Hounslow?"

"Yes, sir, and they have already got out the coloured lights and the ground flares."

"You have done well, Jones, but you had better not leave the office to-night. I'm very sorry, but I may want you. This is urgent business; we're up against something this time, and unless Keane and Sharpe have found something out, we're going to be beaten."

"I'll stay, sir, but what about you? This is your third night-sitting, and you've had nothing since lunch. Shall I order supper for you?"

"Oh, thanks, Jones, but I'd forgotten. Yes, you may order me coffee and a sandwich, and get something for yourself. You're getting the strain as well, and I don't want you to break down."

When left alone, Colonel Tempest once more began to pace the soft-carpeted room, much as a captain paces the bridge when his thoughts are unduly disturbed by some untoward event during the watch of the second officer. Every other minute he consulted his watch, and wondered why the time passed so slowly. Twice he rang down to the lobby attendant and asked if Captain Keane had arrived, and twice the same answer was returned.

Then he looked at the maps on the wall, and followed with his finger the trail of the All-Red Route which the aerial liners followed, linking up the empire and half the world. Now and again he would glance shrewdly at the large map of Germany, as a skipper eyes the weather quarter when a storm is brewing. Occasionally he would murmur half aloud:–

"A silent engine … three hundred miles an hour. Gee whiz! but they have beaten us two to one. We shall never catch them."

Then a slight sound caught his ears from outside the great building. The soft purr of an approaching Rolls-Royce motor and the sharp blast of a Klaxon horn followed.

"At last!" he cried. "Here they come!"

CHAPTER IV
A MIDNIGHT CONSULTATION

The next moment the door burst open and two men in flying helmets and leathern coats entered the room, and saluted the Colonel. Without any ceremony the latter greeted them warmly, almost joyously, for their cheerful presence gave almost instant relief to his over-burdened mind.

"Good evening, Keane. Good evening, Sharpe," he exclaimed, stepping forward and gripping each of them warmly by the hand.

"Good evening, sir."

"Now, have you discovered anything?" began the chief, without waiting for them to divest themselves of their heavy gear.

Keane looked at the Commissioner for a second or two and then answered:–

"Yes, and no, Colonel."

"H'm. That means something and nothing, I presume."

"Exactly, sir," continued Keane, who acted the part of spokesman. Then, speaking more solemnly, and in lowered tones, he continued, "We are up against something abnormal; I had almost said something supernatural. When you recalled us we were hot on the trail of the man who, in my opinion, is behind this conspiracy."

"You mean this Professor Weissmann?" added the chief of the aerial police.

Keane nodded.

"I thought so. This man is evidently an evil genius of very high mental calibre, and he has determined, out of personal revenge for the defeat of Germany, to thwart the Allies, and in particular Great Britain."

"He is a master-mind, and a highly dangerous personality; dangerous because he is so clever. And now that he has secured a few daring airmen for his tools, there is no end to the possibilities which his evil genius may accomplish before he and his crew are run to earth," replied Captain Keane.

"I know it, I know it–look here!" and the colonel handed him the batch of cables and wireless messages which showed how the Scorpion had already got to work.

"H'm! and there will be worse to follow," added the airman after he had glanced through the list.

"Now, tell me briefly what you have found, Keane, after which we must get to work to devise some immediate plan to thwart these aerial brigands. But first take off your flying gear, and sit by the fire, for you must be hungry, tired and numbed after that cold night ride." Then, ringing for his attendant, he ordered up more strong coffee and sandwiches.

"Thanks, Colonel, I will not refuse. It was indeed a cold ride, and we had no time to get refreshments before leaving the aerodrome at Cologne this evening," said Sharpe, as he divested himself of his heavy gear, sat by the fire and enjoyed the coffee which soon arrived.

A few moments later, the three men were engaged in serious conversation, although the hour of midnight had long since been tolled out by Big Ben.

"You sent me," Keane was saying, "to discover the whereabouts of this great German engineer and man of science, this brain wave whose perverted genius is likely to cost us so dear."

"And you were unable to find any trace of him?" interposed the chief.

"Well, we were unable to come into contact with him, for we found that since peace was concluded he had vacated his professorial chair at Heidelberg University, where he had been engaged for some considerable time, not only on some mechanical production, but in an attempt to discover some unknown force, evidently a new kind of highly compressed gas to be used for propulsive purposes."

"Had he been successful?"